#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "defs.h"


/* TABLE_SIZE is the number of entries in the symbol table. */
/* TABLE_SIZE must be a power of two.			    */

#define	TABLE_SIZE 1024


bucket **symbol_table;
bucket *first_symbol;
bucket *last_symbol;


int hash(char *name)
{
char *s;
int c, k;

  assert(name && *name);
  s = name;
  k = *s;
  while ((c = (int)*(++s))!=0)
	 k = (31*k + c) & (TABLE_SIZE - 1);
  return (k);
}


bucket *make_bucket(char *name)
{
bucket *bp;

  assert(name);
  bp = (bucket *) allocate(sizeof(bucket));
  if (bp == 0) no_space();
  bp->link = 0;
  bp->next = 0;
  bp->name = allocate(strlen(name) + 1);
  if (bp->name == 0) no_space();
  bp->tag = 0;
  bp->value = UNDEFINED;
  bp->index = 0;
  bp->prec = 0;
  bp-> class = UNKNOWN;
  bp->assoc = TOKEN;
  if (bp->name == 0) no_space();
  strcpy(bp->name, name);
  return (bp);
}


bucket *lookup(char *name)
{
bucket *bp, **bpp;

  bpp = symbol_table + hash(name);
  bp = *bpp;

  while (bp)
    {
	 if (strcmp(name, bp->name) == 0) return (bp);
	 bpp = &bp->link;
	 bp = *bpp;
    }

  *bpp = bp = make_bucket(name);
  last_symbol->next = bp;
  last_symbol = bp;

  return (bp);
}


void create_symbol_table(void)
{
int i;
bucket *bp;

  symbol_table = (bucket **) allocate(TABLE_SIZE*sizeof(bucket *));
  if (symbol_table == 0) no_space();
  for (i = 0; i < TABLE_SIZE; i++)
	symbol_table[i] = 0;

  bp = make_bucket("error");
  bp->index = 1;
  bp->class = TERM;

  first_symbol = bp;
  last_symbol = bp;
  symbol_table[hash("error")] = bp;
}


void free_symbol_table(void)
{
    FREE(symbol_table);
    symbol_table = 0;
}


void free_symbols(void)
{
bucket *p, *q;

  for (p = first_symbol; p; p = q)
    {
	 q = p->next;
	 FREE(p);
    }
}

